The waveforms have different MFSK parameters such as tones, baudrate and shift: probably
they not involve all code combinations but the signals are certainly
very similar and probably sent by the same equipment.

These signals seem to be experiment/tests with a new Serdolik set of MFSK waveforms, something like a combination of a call (or perhaps ALE Selcall) and data-sending. The s4 MFSK-32 waveform is reported as "new" also in radioscanner.ru, but in that post is used with OFDM-60 as a starting combination while here is used also as 'stand-alone' in burst mode. Interestingly the lack of the CIS-60 pilot-tone at the usual 3300 Hz: this could indicate the preamble purposes of the initial MFSK-32 tones. Also in this case, the burst mode is used.

MFSK-32 used as sort of CIS-60 preamble

An interesting difference - at least in these samples - between s1, s2 and s4 are the directions of the two initial sweeps (s3 has a different initial structure): in s1 and s2 the initial sweeps are upward while s4 has downward sweeps. In these recordings s2 carries the same data.

Other than the above post (by my friend KarapuZ) in radioscanner.ru forum, I could not find any other info/report about these waveforms: if they are on-air just from a few days we'll probably have the chance to read other logs and info in next days or weeks.